Compaction of tantalum or valve powder to make capacitor elements is known in the art as evidenced by the disclosure of U.S. Pat. No. 5,949,639 issued Sep. 7, 1999 to T. Malda et al. for a Capacitor Element for Solid Electrolytic Capacitor, Device and Process for Making the Same and by the disclosure of U.S. Pat. No. 6,191,936 issued Feb. 20, 2001 to D. A. Webber et al. for a Capacitor Having Textured Pellet and Method for Making Same.
When making capacitor anodes by compaction of valve powder it is desired to have uniform compaction. However when the capacitor element has an irregular exterior surface the compaction device typically does not produce a uniformly compacted capacitor element. It has also been found that the capacitor element may be damaged by the withdrawal of the punches used in forming such an element.